/*
RSA Data Security, Inc., MD5 message-digest algorithm

Copyright (C) 1991-2, RSA Data Security, Inc. Created 1991. All rights reserved.

License to copy and use this software is granted provided that it is identified
as the "RSA Data Security, Inc. MD5 Message-Digest Algorithm" in all material 
mentioning or referencing this software or this function.

License is also granted to make and use derivative works provided that such works 
are identified as "derived from the RSA Data Security, Inc. MD5 Message-Digest 
Algorithm" in all material mentioning or referencing the derived work.

RSA Data Security, Inc. makes no representations concerning either the 
merchantability of this software or the suitability of this software for any 
particular purpose. It is provided "as is" without express or implied warranty of 
any kind.

These notices must be retained in any copies of any part of this documentation 
and/or software.
*/

#ifndef __MD5_H__
#define __MD5_H__

#ifndef _MSC_VER
#include "JITInterface.h"
#include "JITCstring.h"
#else
#include <tchar.h>
#include <memory>
#include <atlfile.h>
using namespace ATL;
#endif
using namespace std;

#define	MD5_HASH_LEN					16

typedef struct tagMD5_HASH
{
	unsigned char	pbHashValue[MD5_HASH_LEN];
	TCHAR			szHashValue[(MD5_HASH_LEN + 1) * 2];
} MD5_HASH, *LPMD5_HASH;

// MD5 context.
typedef struct tagMD5_CTX
{
	unsigned long int	state[4];		// state (ABCD)
	unsigned long int	count[2];		// number of bits, modulo 2^64 (lsb first)
	unsigned char		buffer[64];		// input buffer
} MD5_CTX;

// MD5 basic transformation. Transforms state based on block.
inline void MD5Transform(unsigned long int state[4], unsigned char block[64])
{

// Constants for MD5Transform routine.
#define S11 7
#define S12 12
#define S13 17
#define S14 22
#define S21 5
#define S22 9
#define S23 14
#define S24 20
#define S31 4
#define S32 11
#define S33 16
#define S34 23
#define S41 6
#define S42 10
#define S43 15
#define S44 21

// F, G, H and I are basic MD5 functions.
#define F1(x, y, z) (((x) & (y)) | ((~x) & (z)))
#define G(x, y, z) (((x) & (z)) | ((y) & (~z)))
#define H(x, y, z) ((x) ^ (y) ^ (z))
#define I(x, y, z) ((y) ^ ((x) | (~z)))

// ROTATE_LEFT rotates x left n bits.
#define ROTATE_LEFT(x, n) (((x) << (n)) | ((x) >> (32-(n))))

// FF, GG, HH, and II transformations for rounds 1, 2, 3, and 4.
// Rotation is separate from addition to prevent recomputation.
#define FF(a, b, c, d, x, s, ac) { \
	(a) += F1 ((b), (c), (d)) + (x) + (unsigned long int)(ac); \
	(a) = ROTATE_LEFT ((a), (s)); \
	(a) += (b); \
	}
#define GG(a, b, c, d, x, s, ac) { \
	(a) += G ((b), (c), (d)) + (x) + (unsigned long int)(ac); \
	(a) = ROTATE_LEFT ((a), (s)); \
	(a) += (b); \
	}
#define HH(a, b, c, d, x, s, ac) { \
	(a) += H ((b), (c), (d)) + (x) + (unsigned long int)(ac); \
	(a) = ROTATE_LEFT ((a), (s)); \
	(a) += (b); \
	}
#define II(a, b, c, d, x, s, ac) { \
	(a) += I ((b), (c), (d)) + (x) + (unsigned long int)(ac); \
	(a) = ROTATE_LEFT ((a), (s)); \
	(a) += (b); \
	}

	unsigned long int a = state[0], b = state[1], c = state[2], d = state[3], x[16];
	unsigned int i, j;

	for (i = 0, j = 0; j < 64; i++, j += 4)
	{
		x[i] = ((unsigned long int)block[j]) | (((unsigned long int)block[j+1]) << 8) |
			(((unsigned long int)block[j+2]) << 16) | (((unsigned long int)block[j+3]) << 24);
	}

	// Round 1
	FF (a, b, c, d, x[ 0], S11, 0xd76aa478); /* 1 */
	FF (d, a, b, c, x[ 1], S12, 0xe8c7b756); /* 2 */
	FF (c, d, a, b, x[ 2], S13, 0x242070db); /* 3 */
	FF (b, c, d, a, x[ 3], S14, 0xc1bdceee); /* 4 */
	FF (a, b, c, d, x[ 4], S11, 0xf57c0faf); /* 5 */
	FF (d, a, b, c, x[ 5], S12, 0x4787c62a); /* 6 */
	FF (c, d, a, b, x[ 6], S13, 0xa8304613); /* 7 */
	FF (b, c, d, a, x[ 7], S14, 0xfd469501); /* 8 */
	FF (a, b, c, d, x[ 8], S11, 0x698098d8); /* 9 */
	FF (d, a, b, c, x[ 9], S12, 0x8b44f7af); /* 10 */
	FF (c, d, a, b, x[10], S13, 0xffff5bb1); /* 11 */
	FF (b, c, d, a, x[11], S14, 0x895cd7be); /* 12 */
	FF (a, b, c, d, x[12], S11, 0x6b901122); /* 13 */
	FF (d, a, b, c, x[13], S12, 0xfd987193); /* 14 */
	FF (c, d, a, b, x[14], S13, 0xa679438e); /* 15 */
	FF (b, c, d, a, x[15], S14, 0x49b40821); /* 16 */

	// Round 2
	GG (a, b, c, d, x[ 1], S21, 0xf61e2562); /* 17 */
	GG (d, a, b, c, x[ 6], S22, 0xc040b340); /* 18 */
	GG (c, d, a, b, x[11], S23, 0x265e5a51); /* 19 */
	GG (b, c, d, a, x[ 0], S24, 0xe9b6c7aa); /* 20 */
	GG (a, b, c, d, x[ 5], S21, 0xd62f105d); /* 21 */
	GG (d, a, b, c, x[10], S22,  0x2441453); /* 22 */
	GG (c, d, a, b, x[15], S23, 0xd8a1e681); /* 23 */
	GG (b, c, d, a, x[ 4], S24, 0xe7d3fbc8); /* 24 */
	GG (a, b, c, d, x[ 9], S21, 0x21e1cde6); /* 25 */
	GG (d, a, b, c, x[14], S22, 0xc33707d6); /* 26 */
	GG (c, d, a, b, x[ 3], S23, 0xf4d50d87); /* 27 */

	GG (b, c, d, a, x[ 8], S24, 0x455a14ed); /* 28 */
	GG (a, b, c, d, x[13], S21, 0xa9e3e905); /* 29 */
	GG (d, a, b, c, x[ 2], S22, 0xfcefa3f8); /* 30 */
	GG (c, d, a, b, x[ 7], S23, 0x676f02d9); /* 31 */
	GG (b, c, d, a, x[12], S24, 0x8d2a4c8a); /* 32 */

	// Round 3
	HH (a, b, c, d, x[ 5], S31, 0xfffa3942); /* 33 */
	HH (d, a, b, c, x[ 8], S32, 0x8771f681); /* 34 */
	HH (c, d, a, b, x[11], S33, 0x6d9d6122); /* 35 */
	HH (b, c, d, a, x[14], S34, 0xfde5380c); /* 36 */
	HH (a, b, c, d, x[ 1], S31, 0xa4beea44); /* 37 */
	HH (d, a, b, c, x[ 4], S32, 0x4bdecfa9); /* 38 */
	HH (c, d, a, b, x[ 7], S33, 0xf6bb4b60); /* 39 */
	HH (b, c, d, a, x[10], S34, 0xbebfbc70); /* 40 */
	HH (a, b, c, d, x[13], S31, 0x289b7ec6); /* 41 */
	HH (d, a, b, c, x[ 0], S32, 0xeaa127fa); /* 42 */
	HH (c, d, a, b, x[ 3], S33, 0xd4ef3085); /* 43 */
	HH (b, c, d, a, x[ 6], S34,  0x4881d05); /* 44 */
	HH (a, b, c, d, x[ 9], S31, 0xd9d4d039); /* 45 */
	HH (d, a, b, c, x[12], S32, 0xe6db99e5); /* 46 */
	HH (c, d, a, b, x[15], S33, 0x1fa27cf8); /* 47 */
	HH (b, c, d, a, x[ 2], S34, 0xc4ac5665); /* 48 */

	// Round 4
	II (a, b, c, d, x[ 0], S41, 0xf4292244); /* 49 */
	II (d, a, b, c, x[ 7], S42, 0x432aff97); /* 50 */
	II (c, d, a, b, x[14], S43, 0xab9423a7); /* 51 */
	II (b, c, d, a, x[ 5], S44, 0xfc93a039); /* 52 */
	II (a, b, c, d, x[12], S41, 0x655b59c3); /* 53 */
	II (d, a, b, c, x[ 3], S42, 0x8f0ccc92); /* 54 */
	II (c, d, a, b, x[10], S43, 0xffeff47d); /* 55 */
	II (b, c, d, a, x[ 1], S44, 0x85845dd1); /* 56 */
	II (a, b, c, d, x[ 8], S41, 0x6fa87e4f); /* 57 */
	II (d, a, b, c, x[15], S42, 0xfe2ce6e0); /* 58 */
	II (c, d, a, b, x[ 6], S43, 0xa3014314); /* 59 */
	II (b, c, d, a, x[13], S44, 0x4e0811a1); /* 60 */
	II (a, b, c, d, x[ 4], S41, 0xf7537e82); /* 61 */
	II (d, a, b, c, x[11], S42, 0xbd3af235); /* 62 */
	II (c, d, a, b, x[ 2], S43, 0x2ad7d2bb); /* 63 */
	II (b, c, d, a, x[ 9], S44, 0xeb86d391); /* 64 */

	state[0] += a;
	state[1] += b;
	state[2] += c;
	state[3] += d;

	// Zeroize sensitive information.
	//memset(x, 0, sizeof(x));
    RtlSecureZeroMemory(x, sizeof(x));
}

// MD5 initialization. Begins an MD5 operation, writing a new context.
inline void MD5Init(MD5_CTX *context)
{
	context->count[0] = context->count[1] = 0;

	// Load magic initialization constants.
	context->state[0] = 0x67452301;
	context->state[1] = 0xefcdab89;
	context->state[2] = 0x98badcfe;
	context->state[3] = 0x10325476;
}

// MD5 block update operation. Continues an MD5 message-digest operation, 
// processing another message block, and updating the context.
inline void MD5Update(MD5_CTX *context, unsigned char *input, unsigned int inputLen)
{
	unsigned int i, index, partLen;

	// Compute number of bytes mod 64
	index = (unsigned int)((context->count[0] >> 3) & 0x3F);

	// Update number of bits
	if ((context->count[0] += ((unsigned long int)inputLen << 3)) < ((unsigned long int)inputLen << 3))
	{
		context->count[1]++;
	}
	context->count[1] += ((unsigned long int)inputLen >> 29);

	partLen = 64 - index;

	// Transform as many times as possible.
	if (inputLen >= partLen)
	{
		memcpy(&context->buffer[index], input, partLen);
		MD5Transform(context->state, context->buffer);

		for (i = partLen; i + 63 < inputLen; i += 64)
		{
			MD5Transform (context->state, &input[i]);
		}

		index = 0;
	}
	else
	{
		i = 0;
	}

	// Buffer remaining input
	memcpy(&context->buffer[index], &input[i], inputLen - i);
}

// MD5 finalization. Ends an MD5 message-digest operation, writing the
// the message digest and zeroizing the context.
inline void MD5Final(unsigned char digest[16], MD5_CTX *context)
{
	unsigned char bits[8];
	unsigned int index, padLen;
	unsigned int i, j;

	static unsigned char PADDING[64] = {
		0x80, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
		0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
		0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
	};

	// Save number of bits
	for (i = 0, j = 0; j < 8; i++, j += 4)
	{
		bits[j] = (unsigned char)(context->count[i] & 0xff);
		bits[j + 1] = (unsigned char)((context->count[i] >> 8) & 0xff);
		bits[j + 2] = (unsigned char)((context->count[i] >> 16) & 0xff);
		bits[j + 3] = (unsigned char)((context->count[i] >> 24) & 0xff);
	}

	// Pad out to 56 mod 64.
	index = (unsigned int)((context->count[0] >> 3) & 0x3f);
	padLen = (index < 56) ? (56 - index) : (120 - index);
	MD5Update(context, PADDING, padLen);

	// Append length (before padding)
	MD5Update(context, bits, 8);

	// Store state in digest
	for (i = 0, j = 0; j < 16; i++, j += 4)
	{
		digest[j] = (unsigned char)(context->state[i] & 0xff);
		digest[j + 1] = (unsigned char)((context->state[i] >> 8) & 0xff);
		digest[j + 2] = (unsigned char)((context->state[i] >> 16) & 0xff);
		digest[j + 3] = (unsigned char)((context->state[i] >> 24) & 0xff);
	}

	// Zeroize sensitive information.
	memset(context, 0, sizeof(*context));
}

inline void MD5(const void *pBuffer, unsigned int uBufferLen, MD5_HASH *pHash)
{
	if (pBuffer == NULL || uBufferLen == 0 || pHash == NULL)
	{
		return;
	}
	
	MD5_CTX context = {{0}, {0}, {0}};
	MD5Init(&context);
	MD5Update(&context, (unsigned char *)pBuffer, uBufferLen);
	MD5Final(pHash->pbHashValue, &context);

#ifdef _MSC_VER
	for (unsigned int i = 0, j = 0; i < sizeof(pHash->pbHashValue); i++, j += 2)
	{
		#if _MSC_VER >= 1400
			_stprintf_s(pHash->szHashValue + j, 3, _T("%02X"), pHash->pbHashValue[i]);
		#else
			_stprintf(pHash->szHashValue + j, _T("%02X"), pHash->pbHashValue[i]);
		#endif		
	}
#else
	for (unsigned int i = 0, j = 0; i < sizeof(pHash->pbHashValue); i++, j += 2)
	{
		_stprintf_s(pHash->szHashValue + j, 3, _T("%02X"), pHash->pbHashValue[i]);	
	}
#endif
}

#ifdef _MSC_VER
inline BOOL MD5_File(LPCTSTR lpszFilename, MD5_HASH *pHash)
{
    if(lpszFilename == NULL || _tcslen(lpszFilename) == 0)
    {
        return FALSE;
    }

    CAtlFile file;
    if(file.Create(lpszFilename, GENERIC_READ, FILE_SHARE_READ, OPEN_EXISTING) != S_OK)
    {
        return FALSE;
    }

    DWORD nFileSize = 0;
    ULONGLONG ullSize = 0;
    if(file.GetSize(ullSize) != S_OK)
    {
        return FALSE;
    }
    nFileSize = (DWORD)ullSize;

    char *pBuffer = new char[nFileSize + 1];
    ZeroMemory(pBuffer, nFileSize + 1);
    DWORD nReadSize = nFileSize;
    if(file.Read(pBuffer, nFileSize + 1, nReadSize) != S_OK)
    {
        delete [] pBuffer ;
        return FALSE;
    }

    if(nReadSize != nFileSize)
    {
        delete [] pBuffer ;
        return FALSE;
    }

    MD5((const void *)(pBuffer), (unsigned int)nReadSize, pHash);
    delete [] pBuffer ;
    return TRUE;
}
#else
inline BOOL MD5_File(LPCTSTR lpszFilename, MD5_HASH *pHash)
{
	if(lpszFilename == NULL || _tcslen(lpszFilename) == 0)
	{
		return FALSE;
	}

	FILE *file = NULL;
	if((file = fopen((LPCSTR)CStringA(lpszFilename), "r")) == NULL){
		return FALSE;
	}

	DWORD nFileSize = 0;
	struct stat buf;
	if(stat((LPCSTR)CStringA(lpszFilename), &buf)){
		return FALSE;
	}

	nFileSize = buf.st_size;

	char *pBuffer = new char[nFileSize + 1];
	ZeroMemory(pBuffer, nFileSize + 1);
	DWORD nReadSize = nFileSize;

	nReadSize = fread(pBuffer, nFileSize, 1, file);
	if(nReadSize != nFileSize)
	{
		delete [] pBuffer ;
		return FALSE;
	}

	MD5((const void *)(pBuffer), (unsigned int)nReadSize, pHash);
	delete [] pBuffer ;

	fclose(file);
	file = NULL;

	return TRUE;
}
#endif

#endif	/*__MD5_H__*/